Angular JS Interview Questions and Answers

AngularJS is quickly becoming the dominant JavaScript framework for professional web development. With the growth and strength of HTML5 and the increasing performance in modern browsers, many JavaScript frameworks have been created to help develop rich client applications. These frameworks/libraries have given developers a huge toolkit to build enterprise complexity into client-side applications. Server side frameworks are becoming a thing of the past and being replaced with applications written in Backbone, Ember, AngularJS, Knockout, etc.

So why am I talking about AngularJS over frameworks/libraries like Backbone, Ember, or Knockout?

For me, the major points of separation in AngularJSís favor are the following:

1. Good documentation

2. Write less code to do more

3. Backed by Google

4. Good developer community

5. Simple Data-Binding

6. Small footprint

If youíre looking for a robust, well-maintained framework for any sized project, I strongly recommend that you take a look at AngularJS. It can be downloaded for free at AngularJS.org, which also contains a wealth of information, including the full API documentation, as well as numerous examples and tutorials that cover every facet of front-end web development. Following are some reasons why to choose Angular JS Javascript Framework for front-end web development?

1. Angular JS Framework is developed by Google

Angular is built and maintained by dedicated Google engineers. This one may seem obvious, but itís important to remember that many (not all) frameworks are made by hobbyists in the open source community. While passion and drive have forged frameworks, like Cappucino and Knockout, Angular is built and maintained by dedicated (and highly talented) Google engineers. This means you not only have a large open community to learn from, but you also have skilled, highly-available engineers tasked to help you get your Angular questions answered.

This isnít Googleís first attempt at a JavaScript framework; they first developed their comprehensive Web Toolkit, which compiles Java down to JavaScript, and was used by the Google Wave team extensively. With the rise of HTML5, CSS3, and JavaScript, as both a front-end and back-end language, Google realized that the web was not meant to be written purely in Java.

AngularJS came about to standardize web application structure and provide a future template for how client-side apps should be developed.

Angular JS is being used by a host of applications, ranging from hobby to commercial products. Adoption of AngularJS as a viable framework for client-side development is quickly becoming known to the entire web development community.

Because AngularJS is built by Google, you can be sure that youíre dealing with efficient and reliable code that will scale with your project. If youíre looking for a framework with a solid foundation, Angular is your choice!

2. Angular JS is equipped with a lot of features

If youíre familiar with projects, like QUnit, Mocha or Jasmine, then youíll have no trouble learning Angularís unit-testing API.

Angular, similar to Backbone or JavaScriptMVC, is a complete solution for rapid front-end development. No other plugins or frameworks are necessary to build a data-driven web application. Hereís an overview of Angularís stand-out features:

A) REST Easy. RESTful actions are quickly becoming the standard for communicating from the server to the client. In one line of JavaScript, you can quickly talk to the server and get the data you need to interact with your web pages. AngularJS turns this into a simple JavaScript object, as Models, following the MVVM (Model View View-Model) pattern.

B) MVVM to the Rescue! Models talk to ViewModel objects (through something called the $scope object), which listen for changes to the Models. These can then be delivered and rendered by the Views, which is the HTML that expresses your code. Views can be routed using the $routeProvider object, so you can deep-link and organize your Views and Controllers, turning them into navigable URLs. AngularJS also provides stateless controllers, which initialize and control the $scope object.

C) Data Binding and Dependency Injection. Everything in the MVVM pattern is communicated automatically across the UI whenever anything changes. This eliminates the need for wrappers, getters/setters or class declarations. AngularJS handles all of this, so you can express your data as simply as with JavaScript primitives, like arrays, or as complex as you wish, through custom types. Since everything happens automatically, you can ask for your dependencies as parameters in AngularJS service functions, rather than one giant main() call to execute your code.

D) Extends HTML. Most websites built today are a giant series of <div> tags with little semantic clarity. You need to create extensive and exhaustive CSS classes to express the intention of each object in the DOM. With Angular, you can operate your HTML like XML, giving you endless possibilities for tags and attributes. Angular accomplishes this, via its HTML compiler and the use of directives to trigger behaviors based on the newly-created syntax you write.

E) Makes HTML your Template. If youíre used to Mustache or Hogan.js, then you can quckly grasp the bracket syntax of Angularís templating engine, because itís just HTML. Angular traverses the DOM for these templates, which house the directives mentioned above. The templates are then passed to the AngularJS compiler as DOM elements, which can be extended, executed or reused. This is key, because, now, you have raw DOM components, rather than strings, allowing for direct manipulation and extension of the DOM tree.

F) Enterprise-level Testing. As stated above, AngularJS requires no additional frameworks or plugins, including testing. If youíre familiar with projects, like QUnit, Mocha or Jasmine, then youíll have no trouble learning Angularís unit-testing API and Scenario Runner, which guides you through executing your tests in as close to the actual state of your production application as possible.

These are the fundamental principles that guide AngularJS to creating an efficient, performance-driven, and maintainable front-end codebase. As long as you have a source for storing data, AngularJS can do all of the heavy lifting on the client, while providing a rich, fast experience for the end user.

3. You can learn Angular JS easily

Getting started with AngularJS is incredibly easy. With a few attributes added to your HTML, you can have a simple Angular app up in under 5 minutes!

1. Add the ng-app directive to the <html> tag so Angular knows to run on the page: